From owner-freebsd-net@freebsd.org Mon Apr 20 13:35:47 2020 Return-Path: Delivered-To: freebsd-net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 8F3192C30EB for ; Mon, 20 Apr 2020 13:35:47 +0000 (UTC) (envelope-from ankitraheja09@gmail.com) Received: from mail-wr1-x431.google.com (mail-wr1-x431.google.com [IPv6:2a00:1450:4864:20::431]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 495SPt6XZQz4MWb for ; Mon, 20 Apr 2020 13:35:46 +0000 (UTC) (envelope-from ankitraheja09@gmail.com) Received: by mail-wr1-x431.google.com with SMTP id i10so12159823wrv.10 for ; Mon, 20 Apr 2020 06:35:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=dwFaPcS+NZ6RGvOUqPyibYVD4MPtfDkLiW4w3C5ZW3o=; b=LAulvDNpgBbqU68f/TIaZ9urz4l5eYTkNu2Ju3UnwcBCYR8Pj2OJRVzrsyT8qOLszr zihkZx+Z+IVoElBOpjJVBbdsTPrBCrbnRSgebLVw+l67t8/zOap0Nkq6GYCwBXFst2Xc Rr4Za3crRy0K7cp0+rimnBgzkJJmW/ivzLdzZ+/NYjjUnG5MdljnsPJbbbaEMB5ONl+k SJ7UxU5LRPEoaD8vU2wqHQt1dy9eWX30p/xMH9a8lgVWJ1L+zilNL3Jo4wPsjCnyttq3 465wx/wDmD81ZFV5OeeSPXPH+WuzyhzpQlJSfssVKCmYGO6wt2XCEutTYmPQO07rpLS+ 4Mng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=dwFaPcS+NZ6RGvOUqPyibYVD4MPtfDkLiW4w3C5ZW3o=; b=rH+qnNh0e8xKSaYo6JzzHh22VfIYpJculawshCruKskg9iCphegjb/KvQJ6QrVbvWn 7RYWospb0pyUZvxshR9oIynaPYmsvZx7QbOhoW3431uKr2Ic7axFH35xdVnk0oyyUjnb hueOBcLckmIJd9RLDjOQOoYXW0Pim/5p4sIUUl+qDOdpFCsmLT1dDC6Sc790X3GUPGUK AEMobVRxu2Vc67SLjVLTkq4FN5xi5y5Lu6qQOkW3mkmdag/OUnfkgVj5kBwrlmelcvUv KpI0cqqTsKMvi3raG+vt7z/R3pLgTI9l+b6O+MN9vOGL9VO9Wxzgk/c3IRVGu/eWc6yE NxOA== X-Gm-Message-State: AGi0PubLAMa4EqWH3B1QKNHPkhFqQs775efJAnZHmUr4FfuqcbKssOGg PyhirEssyy6IfPMaADfEO0UJ9izhcqYwRME0KJ9rxc+YwdI= X-Google-Smtp-Source: APiQypKcY/8RrpzALUuFNFdmHgwbnndYRNGKe2DWdGZipHEOk8MEVBaF+nYiv7qPTN5HMEvVMH2XY0yX/NgMnkWTKgs= X-Received: by 2002:adf:f450:: with SMTP id f16mr18842148wrp.346.1587389744885; Mon, 20 Apr 2020 06:35:44 -0700 (PDT) MIME-Version: 1.0 From: ankit raheja Date: Mon, 20 Apr 2020 19:05:32 +0530 Message-ID: Subject: BBR States transition from ProbeRTT to StartUP To: freebsd-net@freebsd.org X-Rspamd-Queue-Id: 495SPt6XZQz4MWb X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=LAulvDNp; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of ankitraheja09@gmail.com designates 2a00:1450:4864:20::431 as permitted sender) smtp.mailfrom=ankitraheja09@gmail.com X-Spamd-Result: default: False [-3.00 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+ip6:2a00:1450:4000::/36]; FREEMAIL_FROM(0.00)[gmail.com]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-net@freebsd.org]; TO_DN_NONE(0.00)[]; IP_SCORE_FREEMAIL(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; IP_SCORE(0.00)[ip: (-9.09), ipnet: 2a00:1450::/32(-2.34), asn: 15169(-0.43), country: US(-0.05)]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; RCVD_IN_DNSWL_NONE(0.00)[1.3.4.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.5.4.1.0.0.a.2.list.dnswl.org : 127.0.5.0]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com.dwl.dnswl.org : 127.0.5.0] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Apr 2020 13:35:47 -0000 Hi, I have a query regarding BBR States transition from ProbeRTT to Startup State. As per the code, when a TCP connection leaves Startup State, the variable "bbr->rc_filled_pipe" gets set to 1. When the same connection decided to exit from the ProbeRTT state, it invokes the bbr_exit_probe_rtt() API, where it tried to transit either to Startup State or ProbeBW state based upon the bbr->rc_filled_pipe. If the bbr->rc_filled_pipe has a value 1, it will transit to ProbeBW otherwise to Startup State. *Further, no where in the code, the bbr->rc_filled_pipe is getting set to 0.* Can you please help me, under which scenario the connection can again enter to Startup state? Or It would never get into the Startup State again? Should not we set the rc_filled_pipe = 0 when we come to the Probe state from Drain or Startup state. In addition to this if we get into the state of SUB_DRAIN then we can set this to rc_filled_pipe. Any time we transition to any state then it should be set to 0. Please provide your valuable inputs on the same. Thanks, Ankit